Serologic characteristics and clinical significance of Miltenberger antibodies among Chinese patients in Hong Kong

Perceptions and Experiences of Migrants in Korea Regarding Blood Donation in Association with Sociodemographic Status

Background

With increasing number of migrants in Korea, there is an increasing need for blood products with rare blood antigens. Accordingly, the role of blood donors among migrants has been acknowledged. We investigated migrants’ experiences and perceptions of blood donation along with their sociodemographic status and identified the effects on self-reported blood donation status.

Methods

A cross-sectional survey using a self-developed, structured questionnaire was conducted on 479 migrants. The questionnaire included items about experiences, knowledge, and perceptions on blood donation and sociodemographic factors of respondents.

Results

Most migrants in this study were from Southeast Asia (54.7%) or China (39.9%). Among them, 28.6% (N=137) had donated blood previously, and 2.7% (N=13) had previously donated blood in Korea. All previous blood donors were volunteers, and the two major deterrents of blood donation for non-donors were the fear of pain and lack of knowledge about blood donation. In multivariable logistic regression analysis, the country of birth (odds ratio [OR]=2.65, P<0.001 [China]; OR=4.85, P=0.001 [countries other than China and Southeast Asian countries]) and employment status (OR=2.80, P=0.034) were independently associated with blood donation.

Conclusions

This is the first Korean study to analyze migrants’ experiences and perceptions of blood donation in relation to their sociodemographic status. Our findings can help establish blood donation policies for migrants, devise campaigns to enhance blood donation awareness, and ultimately create a pool of rare blood resources in a multicultural society.

Frequencies of glycophorin variants and alloantibodies against Hil and MINY antigens in Japanese

BACKGROUND AND OBJECTIVES

Antigens of the MNS blood group system are expressed on the red blood cell (RBC) membrane on glycophorin A (GPA) and glycophorin B (GPB) or on hybrid molecules of GPA and GPB. This study investigated the distribution of glycophorin variants and alloantibodies against Hil and MINY among Japanese individuals.

METHODS

Mi(a+) or Hil+ RBCs were screened using an automated blood grouping machine (PK7300) with monoclonal anti-Mi^a or polyclonal anti-Hil. Glycophorin variants were defined by serology with monoclonal antibodies against Mi^a , Vw, MUT and Mur, and polyclonal antibodies against Hil, MINY and Hop + Nob (KIPP). The glycophorin variants were further confirmed by immunoblotting and Sanger sequencing. Alloanti-Hil and alloanti-MINY in the plasma were screened using GP.Hil RBCs in an antiglobulin test. The specificity of anti-Hil or anti-MINY was assessed using GP.Hil (Hil+MINY+) and GP.JL (Hil-MINY+) RBCs.

RESULTS

The GP.HF, GP.Mur, GP.Hut, GP.Vw, GP.Kip and GP.Bun frequencies in 1 005 594 individuals were 0·0357%, 0·0256%, 0·0181%, 0·0017%, 0·0009% and 0·0007%, respectively. GP.Hil was found in as four of the 13 546 individuals (0·0295%). Of 137 370 donors, 10 had anti-Hil (0·0073%) and three had anti-MINY (0·0022%).

CONCLUSIONS

Glycophorin variants were relatively rare in Japanese individuals, with the major variants being GP.HF (0·0357%), GP.Hil (0·0295%) and GP.Mur (0·0256%). Only one example of anti-MINY was previously reported, but we found three more in this study.

Frequency of Mi(a) antigen: A pilot study among blood donors

The Miltenberger (Mi) classes represent a group of phenotypes for red cells that carry low frequency antigens associated with the MNSs blood group system. This pilot study was aimed at determining the Mia antigen positivity in the blood donor population in a tertiary care hospital in New Delhi, India. The study was performed between June to August 2014 on eligible blood donors willing to participate. Antigen typing was performed using monoclonal anti-Mia antiserum by tube technique. Only one of the 1000 blood donors (0.1%) tested was found to be Mia antigen positive. the Mia antigen can, therefore, be considered as being rare in the Indian blood donor population.

Detection of alloimmunization to ensure safer transfusion practice

BACKGROUND

Serological safety is an integral part of overall safety for blood banks. Emphasis is on the use of routinue Red Blood Cell (RBC) antibody screen test, at set time intervals, to reduce risks related to alloantibodies. Also emphasis is on importance of issuing antigen negative blood to alloantibody positive patients. Effect of using leucodepleted blood on the rate of alloimmunization is highlighted. The concept of provision of phenotypically matched blood is suggested.

MATERIALS AND METHODS

Antibody screen test is important to select appropriate blood for transfusion. Repeat antibody screen testing, except if time interval between the earlier and subsequent transfusion was less than 72 hours, followed by antibody identification, if required, was performed in patients being treated with repeat multiple blood transfusions. Between February 2008 and June 2009, repeat samples of 306 multi-transfused patients were analyzed. Search for irregular antibodies and reading of results was conducted using RBC panels (three-cell panel of Column Agglutination Technology (CAT) and two cell panel of the Solid Phase Red Cell Adherence Technology (SPRCAT). Specificities of antibodies were investigated using appropriate panels, 11 cell panel of CAT and 16 cell panel of SPRCA. These technologies, detecting agglutination in columns and reactions in solid phase, evaluate the attachment of irregular incomplete antibody to antigen in the first phase of immunological reaction more directly and hence improve the reading of agglutination. Three to four log leuco reduced red blood cells were transfused to patients in the study using blood collection bags with integral filters.

RESULTS

Alloimmunization rate of 4.24% was detected from 306 multiply transfused patients tested and followed up. The Transfusion therapy may become significantly complicated.

CONCLUSION

Red cell antibody screening and identification and subsequent issue of antigen negative blood have a significant role in improving blood safety. Centers that have incorporated antibody screen test and identification have ensured safe transfusion. Identified patients should be flagged in a database and information shared. Such patients can be given carry-on cards and educated about the names of the identified antibodies. Full red cell phenotyping of individuals, patients and donors, can be feasibility.

Frequencies and specificities of red cell alloantibodies in the Southern Thai population

CONTEXT

Detailed reports of red cell alloantibody frequencies and specificities in the Thai population are limited. The aims of this study were to determine the specificity and compare the frequency of alloantibodies detected using column agglutination technology (CAT) and conventional tube techniques in blood donors and previously transfused patients.

SETTINGS AND DESIGN

WE RETROSPECTIVELY REVIEWED ANTIBODY SCREENING AND IDENTIFICATION RECORDS FOR TWO TIME PERIODS: January-December 2006 during which conventional tube techniques were used and January 2008-December 2009 when CAT was used.

RESULTS

The overall prevalence of alloantibodies in both patients and donors when using conventional tube techniques was 0.7%, for patients only was 0.9% and donors 0.6%. The most frequent antibodies detected in both groups were anti-Le(a), anti-Mi(a), anti-Le(b), anti-P1 and anti-E. When using CAT, alloantibodies were found in 0.8% of patients and 0.13% of donors with the five most common alloantibodies found in patients were anti-Mi(a), anti-E, anti-Le(a), anti-c and anti-Le(b) respectively. Similarly the common alloantibody specificities in donors were anti-Le(a), anti-Mi(a), anti-Le(b), anti-M and anti-D.

CONCLUSIONS

One of the most commonly identified alloantibodies in the Thai population studied was anti-Mi(a) suggesting that Mia positive red cells should routinely be included in antibody screening and identification in this population. For antibody screening and identification, CAT method detected immune and warm alloantibody (ies) more frequently than that associated with conventional tube techniques.

Prevalence and specificity of red-blood-cell antibodies in a multiethnic South and East Asian patient population and influence of using novel MUT+Mur+ kodecytes on its detection

BACKGROUND AND OBJECTIVES

Appropriate screening for irregular red-cell antibodies is essential for ensuring transfusion compatibility and for antenatal management of mothers at risk of haemolytic disease of the foetus and newborn. Screening for all relevant antibodies is, however, limited by screening cells that do not express antigens present in the patient and donor population. Technology to artificially incorporate antigens into red cells is currently available and may be an option for customizing screening cells.

MATERIALS AND METHODS

We sought to identify retrospectively the changing patterns of alloantibody prevalence in our multiethnic population on change of screening cells. Antibody screening records of 143 501 patients tested from 2004 to 2010 were retrieved and divided into two groups: period-1 (2004-2008) and period-2 (2009-2010). During period-1, standard screening cells were used while in period-2, MUT+Mur+ KODE(™) transformed red cells (kodecytes) were used.

RESULTS

Four per cent of samples tested during period-2 were positive on antibody screening compared to 3·2% in period-1. Specific antibodies, excluding anti-D, were identified in 1·66% and 1·52% of patients in period-2 and -1, respectively. When confined to antibodies of clinical significance only, period-2 showed higher alloantibody prevalence of 1·16% as compared to 0·66% in period-1. Antibodies to glycophorin variants of MNS (vMNS) were more commonly detected while antibodies to Lewis antigens declined during period-2.

CONCLUSION

  Antibodies to vMNS antigens are common in South and East Asian populations and are often missed when using standard screening cells. Use of specifically engineered screening cells to express red-cell antigens artificially is beneficial in detecting the diverse alloantibodies present in our population.

Sixty years of antibodies to MNS system hybrid glycophorins: what have we learned?

The MNS system was the second blood group system discovered and at least 16 of the 46 antigens in the MNS system result from genetic recombination, producing a hybrid glycophorin. The incidence of these hybrid glycophorins is highest in East Asian populations. MNS system antigens defined by hybrid glycophorins are immunogenic with alloimmune IgG responses developing after transfusion or pregnancy; with reports originating from Asia, Europe, the Americas, and Australia. This demonstrates the global nature of problems associated with these antibodies. Since the initial report that production of anti-Mi(a) was a cause of hemolytic disease of the fetus and newborn (HDFN), antibodies to antigens defined by hybrid glycophorins have been reported in 27 cases of HDFN (1 fatal) and 8 cases of hemolytic transfusion reaction (HTR) (1 fatal). In at least 40% of these clinical cases, the disease was reported as severe. Hyporegenerative fetal anemia is a common feature of the reported HDFN cases. In all published cases, the causative antibodies were identified by reference laboratory investigative tests following clinical presentation. The failure to detect these antibodies by routine testing highlights the need for consideration of the medical importance of these antibodies when defining antibody screening practices and reagents. The aim of this review is to raise awareness of severe disease caused by antibodies to MNS antigens defined by hybrid glycophorins and, thus, to improve diagnosis and patient management.

Anti-"Mi(a)" immunization is associated with HLA-DRB1*0901

BACKGROUND

Anti-"Mi(a)" is one of the most important irregular red blood cell antibodies found in Taiwan. The aim of this study was to investigate whether specific HLA-DRB1 alleles are associated with anti-"Mi(a)" production.

STUDY DESIGN AND METHODS

A case-control retrospective study was performed on 68 patients showing presence of anti-"Mi(a)" and 219 unrelated control subjects from the Mackay Memorial Hospital. HLA-DRB1 genotyping was carried out using sequence-based typing method. Fisher's exact test using 2 x 2 contingency tables was used to analyze significance of the association between DRB1 polymorphisms and presence of anti-"Mi(a)" in patients.

RESULTS

HLA-DRB1*0901 allele frequency in the anti-"Mi(a)" group (30%) was significantly higher than in the control group (16%) with an odds ratio of 2.27 (95% confidence interval, 1.44-3.55; p = 0.0005; p(c) = 0.016).

CONCLUSION

HLA-DRB1*0901 is significantly more prevalent in the anti-"Mi(a)" patients group than in the control group. It is suggested that cells from DR9 individuals might present processed "Mi(a)" antigen-allospecific peptides more effectively than cells from individuals carrying other DR phenotypes. Finally, it was predicted that two epitopes, derived from the MiIII glycophorin amino acid sequence, were likely to bind preferentially with the DR9 molecule. Further work will be necessary to determine if these epitopes are responsible for anti-"Mi(a)" alloimmunization.

Red blood cell alloantibodies and liver transplantation in Chinese patients

BACKGROUND

Red blood cell (RBC) alloantibodies are present in up to 14% of white recipients of liver transplants and can cause severe delayed hemolysis.

METHODS

A retrospective survey showed 17 cases (8.8%) of RBC alloantibodies in 192 consecutive Chinese recipients of liver transplants compared with a background hospital incidence of 3.7%.

RESULTS

The spectrum of RBC alloantibodies in Chinese patients was different than in white patients, with no anti-D or anti-K antibodies but a significant incidence of anti-Mi (29%) antibodies. There was a significantly increased incidence of transfusions in RBC alloantibody positive cases. Delayed hemolysis also resulted in higher day-7 bilirubin levels. A total of 7 to 86 antigen-positive units were issued in five RBC alloantibody cases, including three early deaths. Seven cases in the RBC alloantibody negative group, but none in the positive group, were salvaged by regraft.

CONCLUSIONS

Blood banks servicing transplant centers should be aware of ethnic patterns in RBC alloantibodies. Delayed hemolysis may jeopardize patient survival as the result of difficult postoperative stabilization, especially in cases requiring massive transfusion.

Red blood cell alloantibodies and liver transplantation in Chinese patients

Red blood cell (RBC) alloantibodies are present in up to 14% of white recipients of liver transplants and can cause severe delayed hemolysis. A retrospective survey showed 17 cases (8.8%) of RBC alloantibodies in 192 consecutive Chinese recipients of liver transplants, compared with a 3.7% background hospital incidence. The spectrum of RBC alloantibodies was different from that in white recipients, with no anti-D or anti-K antibodies but with a significant incidence of anti-Mi (29%) antibodies. There was significantly increased transfusion in RBC alloantibody positive cases. Delayed hemolysis also resulted in higher day-7 bilirubin levels. A total of 7 to 86 antigen-positive units were issued in five RBC alloantibody cases, including three early deaths. Seven cases in the RBC alloantibody negative group, but none in the positive group, were salvaged by regraft. Blood banks servicing transplant centers should be aware of ethnic patterns in RBC alloantibodies. Delayed hemolysis may jeopardize patient survival as a result of difficult postoperative stabilization, especially in cases requiring massive transfusion.

Immunological characterization of anti-Mi(a), a red blood cell alloantibody, in Taiwan

BACKGROUND AND OBJECTIVES

The red blood cell Mi III phenotype is prevalent in Asia, and its corresponding alloantibody, anti-Mi(a), has been reported to cause haemolytic transfusion reactions and haemolytic disease of the newborn. However, a complete picture of the immunological characteristics of anti-Mi(a) is still lacking. We therefore conducted a systematic study to evaluate the potential clinical significance of this antibody.

MATERIALS AND METHODS

From April 1999 to March 2000, we identified 60 sera containing anti-Mi(a) among pretransfusion samples at a teaching hospital in Taiwan. These antibodies were tested for immunoglobulin class, thermal range and activity in a monocyte monolayer assay.

RESULTS

Thirty-four (57%) of the antibodies were immunoglobulin M (IgM), and 15 retained their activity at 37 degrees C. Of those that were immunoglobulin G (IgG), 96% were of subclasses IgG1 and/or IgG3. Monocyte monolayer assay studies showed that 69% (18/26) of the IgG anti-Mi(a) sera were reactive.

CONCLUSIONS

Our study justifies the implementation of anti-Mi(a) screening in Taiwan.

To err is human nature. Can transfusion errors due to human factors ever be eliminated?

BACKGROUND

Fatal hemolytic transfusion reaction due to ABO incompatibility occurs mainly as a result of clerical errors. Blood sample drawn from the wrong patient and labeled as another patient's specimen will not be detected by the blood bank unless there is a previous ABO grouping result.

METHODS

In Hong Kong, we had designed a transfusion wristband system--portable barcode scanner system to detect such clerical errors. The system was well accepted by the house staff and had prevented two BO mismatched transfusion. Other current system of patient's identification may have similar results, but the wristband system has the advantages of being simple, inexpensive and easy to implement. The Hong Kong Government is planning to replace the personal identity card for all citizens with an electronic smart card by 2003. If the new card contains the person's detailed red cell phenotypes in digital code, then the phenotypes of all blood donors and admitted patients will be readily available. It is feasible to issue phenotype-matched blood to patients without any need of pre-transfusion testing, therefore eliminating mismatched transfusions for most patients.

RESULTS

Our pilot study of 474 patients showed that the system was safe and up to 98% of admitted patients could be transfused without delays.

CONCLUSIONS

Patients with rare phenotypes, visitors or illegal immigrants may still need pre-transfusion antibody screen, but if most patients can be issued blood units without testings, the potential savings in health care amount to US$14 million/year.